An oil pump is a dynamic component, which uses actions of oil pressure thereby realizing dynamic output. It is usually used to be applied in a kind of dismantling tools of automobiles.
For example, Chinese patent discloses a twin pump single cylinder rapid supercharge horizontal jack, with application number 201420604540.6, includes a pedestal, a pressure arm, filling pumps, an oil cylinder being push rod piston, a valve body; the pressure arm is installed on the pedestal, the pressure arm connects to a handle, the pedestal is located on two filling pumps, one end of two filling pumps are parallel and respectively through oil channels to connect with a hydraulic cylinder, the another ends are connected with the pressure arm; a lifting arm is mounted on the pedestal, one end of the lifting arm body through a connector joins with the top head of the oil cylinder, the other end is connected to a tray, the tray bottom is connected with a link rod, the other end of the link rod is fixed on the pedestal; an underpart of the pedestal is fastened to roll wheels. The present scheme is a kind of horizontal jack, which uses the two filling pumps for rapidly supercharging to rise substances, quickly reaching to the top level, its bottom is mounted with wheels, moves conveniently, saves power high efficiency; the handle uses telescopic laminar multi-section handle, is folding, the whole machine is easily carried.
The above-mentioned scheme although has above-mentioned many advantages, the scheme at least has below shortcomings: the filling oil pumps in the loading conditions (when intermittent motion and high flow speed), its inner low press overflow valve owing oil pressure every time gradually rising to cause the valve every time gradually being started, and the low press overflow valve every time in the starting process, there is all to generate larger noise when a hydraulic oil flows through the low press overflow valve, the practicality is bad.